| // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "ltsh.h" |
| |
| #include "maxp.h" |
| |
| // LTSH - Linear Threshold |
| // http://www.microsoft.com/typography/otspec/ltsh.htm |
| |
| #define TABLE_NAME "LTSH" |
| |
| #define DROP_THIS_TABLE(...) \ |
| do { \ |
| OTS_FAILURE_MSG_(file, TABLE_NAME ": " __VA_ARGS__); \ |
| OTS_FAILURE_MSG("Table discarded"); \ |
| delete file->ltsh; \ |
| file->ltsh = 0; \ |
| } while (0) |
| |
| namespace ots { |
| |
| bool ots_ltsh_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| Buffer table(data, length); |
| |
| if (!file->maxp) { |
| return OTS_FAILURE_MSG("Missing maxp table from font needed by ltsh"); |
| } |
| |
| OpenTypeLTSH *ltsh = new OpenTypeLTSH; |
| file->ltsh = ltsh; |
| |
| uint16_t num_glyphs = 0; |
| if (!table.ReadU16(<sh->version) || |
| !table.ReadU16(&num_glyphs)) { |
| return OTS_FAILURE_MSG("Failed to read ltsh header"); |
| } |
| |
| if (ltsh->version != 0) { |
| DROP_THIS_TABLE("bad version: %u", ltsh->version); |
| return true; |
| } |
| |
| if (num_glyphs != file->maxp->num_glyphs) { |
| DROP_THIS_TABLE("bad num_glyphs: %u", num_glyphs); |
| return true; |
| } |
| |
| ltsh->ypels.reserve(num_glyphs); |
| for (unsigned i = 0; i < num_glyphs; ++i) { |
| uint8_t pel = 0; |
| if (!table.ReadU8(&pel)) { |
| return OTS_FAILURE_MSG("Failed to read pixels for glyph %d", i); |
| } |
| ltsh->ypels.push_back(pel); |
| } |
| |
| return true; |
| } |
| |
| bool ots_ltsh_should_serialise(OpenTypeFile *file) { |
| if (!file->glyf) return false; // this table is not for CFF fonts. |
| return file->ltsh != NULL; |
| } |
| |
| bool ots_ltsh_serialise(OTSStream *out, OpenTypeFile *file) { |
| const OpenTypeLTSH *ltsh = file->ltsh; |
| |
| const uint16_t num_ypels = static_cast<uint16_t>(ltsh->ypels.size()); |
| if (num_ypels != ltsh->ypels.size() || |
| !out->WriteU16(ltsh->version) || |
| !out->WriteU16(num_ypels)) { |
| return OTS_FAILURE_MSG("Failed to write pels size"); |
| } |
| for (uint16_t i = 0; i < num_ypels; ++i) { |
| if (!out->Write(&(ltsh->ypels[i]), 1)) { |
| return OTS_FAILURE_MSG("Failed to write pixel size for glyph %d", i); |
| } |
| } |
| |
| return true; |
| } |
| |
| void ots_ltsh_free(OpenTypeFile *file) { |
| delete file->ltsh; |
| } |
| |
| } // namespace ots |
| |
| #undef TABLE_NAME |
| #undef DROP_THIS_TABLE |